Selectable delay mechanism for pyrotechnic munitions

ABSTRACT

A selectable delay mechanism for a pyrotechnic munition having an indexing sleeve and a fuze core containing delay composition positioned within the indexing sleeve and a plurality of ports each located in the indexing sleeve and the fuze core wherein a port in the indexing sleeve is aligned with a port in the fuze core to vary the initiation of the delay composition.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. Provisional Application Ser. No. 61/038,003, filed on Mar. 19, 2008.

FIELD OF THE INVENTION

The present invention relates to the field of pyrotechnic munitions used to redirect, control or incapacitate targets and specifically, a variable delay system which enables the operator to select the desired engagement distance for the munition.

BACKGROUND OF THE INVENTION

Pyrotechnic munitions can be produced in a number of different configurations and calibers. One configuration type is the burning smoke or riot agent-emitting munition. These munitions are designed to carry their payloads downrange and begin emitting their contents once the predetermined delay time has been reached. Another munition configuration example is the aerial deterrent. In this configuration, the payload is propelled down range and is designed to discharge in the air above the target after the predetermined delay time has been met.

Each munition round type or configuration will employ a delay mechanism designed specifically for that round. Previous types of delays may comprise a simple burning timed fuze, a pressed delay composition or a combination of both. The delays may be initiated directly from the shell discharge itself or by another direct or indirect initiation method.

While prior delay configurations for these munitions employ many advantages and disadvantages, they all share a common problem. The problem is the delay must be designed in conjunction with the intended operational range. This limits the rounds capabilities to a single specific operational distance. The operational distance may hinder the end user's ability to safely discharge the munitions due to lack of, or excessive distance to the target. In addition, users of these munitions must maintain a number of supplies of munitions having various delays so that they are available for a specific application. In addition to storage and transportation issues, errors can be made in selecting a munition having an unintended delay mechanism whereas the munition can detonate prematurely or too late for its intended application. Consequently, a need exists for a variable delay mechanism which enables an operator to select the desired engagement distance for the particular application of the pyrotechnic munition.

SUMMARY OF THE INVENTION

The present invention is directed to a selectable delay mechanism for a pyrotechnic munition that will permit its use at different operational ranges. The delay times, may be physically selected by the operator prior to deployment of the munition. Incorporating a selectable delay mechanism provides for versatility of up to four delay munitions into a single adaptable unit. The selectable delay mechanism of the present invention includes a fuze core, an indexing sleeve and an indexing ring which can be adjusted to select the specific delay time prior to detonation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of the delay mechanism of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS INVENTION (SHOULD BE INVENTION?)

FIG. 1 illustrates the selectable delay mechanism 10 of the present invention. The selectable delay mechanism 10 is for a pyrotechnic munition which permits use of the munition at different operational ranges. The selectable delay mechanism includes a fuze core 12 positioned within an indexing sleeve 14. Fuze core 12 has a hollow cylindrical lower portion 16 for placement of ignitable delay materials 18. The lower portion 16 includes a number of ports 20 running longitudinally along the centerline of the lower tubular portion, each spaced at a specific distance and angle from one another. Three ports are shown in FIG. 1 for illustrative purposes. The lower portion 16 of the fuze core 14 is positioned within a hollow cylindrical interior 22 of the indexing sleeve 14. The fuze core is positioned within and sealed with the hollow interior of the indexing sleeve by a sealing ring 24. Ring 24 is positioned within a groove 26 in the fuze core and a corresponding groove 28 in the indexing sleeve. Sealing ring 24 can be an O-ring or other material used to form a seal between the fuze core and the index sleeve.

Positioned along an upper portion 30 of the fuze core is an index ring 32 which is shaped or keyed in such a way that it is able to move along the centerline axis but not rotationally around the centerline of the mechanism. A pressure spring 34 applies pressure against the index ring and is held in place by a retaining 36.

The fuze core is pressed into the index sleeve until the sealing ring locks in to the grooves within the index sleeve. The index sleeve also has ports 38 along its centerline at a specific distance and angle from one another which line up with corresponding ports 20 in the fuze core, directing the delay emission to the pyrotechnic mix 40 contained within the munition 42. The index sleeve 14 is attached to a lower portion 44 of the main projectile body of the munition 42.

When assembled into the munition 42, the fuze core protrudes slightly from an end of the projectile. A screwdriver or other tool is utilized to select the desired range or delay time by turning the fuze core inside the index sleeve. As the delay core is turning inside the index sleeve, the turning force applied is forcing the index ring up and out of an index groove against pressure applied by the pressure spring. As the fuze core is rotated, pressure on the index ring will cause it to drop in to the next index groove on the index sleeve. In each index position, a port in both the fuze core and index sleeve are in alignment. The further the ports are from the initiation of the delay composition, the longer the delay.

The delay composition contained within the fuze core can consist of a single time delay fuze or multiple strands of timed delay fuze. Alternatively, the selectable delay system can include delay composition consisting of single pressed column delay, a multiple individual pressed column delay, or a single multi-staged pressed column delay.

An alternative arrangement for indexing the fuze core and the index sleeve can be by means of a spring loaded detent pin or other indexing means such as interference grooves, locking rings, set screw or other mechanical fasteners. FIG. 1 illustrates the O-ring/groove orientation as reference numeral 24. However, reference numeral 24 can also be referencing the alternative indexing mechanisms.

Although the present invention has been described and illustrated with respect to a preferred embodiment thereof, it is to be understood that changes and modifications can be made therein which are within the full intended scope of the invention as hereinafter claimed. 

1. A delay mechanism for a munition comprising: an indexing sleeve; a fuze core at least partially positioned within the indexing sleeve; and means for aligning the fuze core within the indexing ring to vary the initiation of delay composition located within the fuze core.
 2. The mechanism of claim 1 wherein the means for aligning the fuze core within the indexing sleeve comprises a plurality of ports in each of the index sleeve and the fuze core wherein a port in the index sleeve is aligned with a port in the fuze core.
 3. The mechanism of claim 1 wherein the means for aligning the fuze core in the index sleeve further comprises an index ring adjacent the indexing sleeve and positioned around the fuze core.
 4. The mechanism of claim 3 wherein the index ring is held under pressure against the indexing sleeve by a spring and a retaining clip positioned around the fuze core.
 5. The mechanism of claim 1 further comprising a sealing ring positioned in a groove between the fuze core and the index sleeve.
 6. The delay mechanism of claim 1 wherein the delay composition located within the fuze core comprises multiple strands of timed delay fuze.
 7. The mechanism of claim 1 wherein the delay composition located within the fuze core comprises a multiple individual pressed column delay.
 8. The mechanism of claim 1 wherein the delay composition located within the fuze core comprises a single multi-staged pressed column delay.
 9. The mechanism of claim 1 wherein the means for aligning the fuze core within the indexing ring can comprise one of a spring-loaded detent pin, interference groove, locking ring, or set screw.
 10. The mechanism of claim 1, wherein the fuze core and indexing sleeve are rotatable with respect to each other.
 11. A pyrotechnic munition comprising: a housing having a pyrotechnic mix; and a selectable delay mechanism for varying deployment times of the munition.
 12. The munition of claim 11 wherein the selectable delay mechanism comprises an indexing sleeve, a fuze core positioned within the indexing sleeve, and a plurality of alignable openings in each of the indexing sleeve and the fuze core.
 13. The munition of claim 11 wherein the selectable delay mechanism further comprises an index ring adjacent the indexing sleeve and positioned around the fuze core.
 14. The munition of claim 13 wherein the index ring is held under pressure against the indexing sleeve by a spring and a retaining clip positioned around a portion of the fuze core.
 15. The munition of claim 12 further comprising a sealing ring positioned in a groove between the fuze core and the index sleeve.
 16. The munition of claim 12 wherein the fuze core includes a delay composition comprising multiple strands of timed delay fuze.
 17. The munition of claim 12 wherein the fuze core includes delay composition comprising a multiple individual pressed column delay.
 18. The munition of claim 12 wherein the fuze core includes a delay composition comprising a single multi-staged pressed column delay.
 19. A method of selecting a detonation time for a pyrotechnic munition having a selectable delay mechanism including a fuze core positioned with an indexing sleeve comprising the steps of: rotating the fuze core and the indexing sleeve with respect to one another; and aligning at least one port in the fuze core with at least one port in the indexing sleeve.
 20. A method of claim 19 further comprising the step of rotating the fuze core and the indexing sleeve with respect to one another to align a second port in the index sleeve with a second port in the fuze core. 